Fig. 7

GhBOP1 positively regulates lignin deposition. a The expression levels of lignin synthesis-related genes in WT and transgenic cotton. Total RNA was extracted from the root of WT and transgenic cotton seedlings. Error bars represent the SD of three biological replicates. The asterisks indicate statistically significant differences compared to corresponding gene expression levels of WT plants, as performed by the Student’s t-test (*P < 0.05, **P < 0.01). b Phloroglucinol-HCl staining of stem sections at the same position in WT and transgenic cottons. The black arrows indicate vascular bunldes in stem across sections. Scale bars = 0.2 mm. c Acid-insoluble lignin residues remained on quantitative filter paper after the Klason extraction. d, e The lignin content of WT and transgenic cotton was measured by the Klason method (d) and thioglycolate (e) analysis, respectively. Error bars represent the SD (n = 18) of three biological replicates. Asterisks indicate statistically significant differences in comparison to WT, as determined by the Student’s t-test (*P < 0.05, **P < 0.01)